Apparatus for separating liquid from pulp fibers



sept. 25, 192s.

J. T. HOYT APPARATUS FOR SEPARATING LIQUID FROM PULP FIBERS Filed Feb. l, 1924 2 Sheets-Sheet 000000090oeooaooooooooooo ooooooooo mma oooooaooooooaoooooooooocuooooooo Oooaooooooeooacooooooooaooaooooooo oooboeoooouooua o oouoeooooooe ooooaoooooacooooaouooooo o0c00n000u e oooo 000000000000000000 00000000000000000000naoaouvoao.o

sept. 25, 192s.

J. T. HOYT APPARATUS FOR SEPARATING LIQUID'FROM PULP FIBERS Filed Fb. l, 1924 2 Sheets-Sheet ai; a: Sooo Sooooa Zocca@ c oooooo 200Go@ oooeoooooo'ooo-I O C O wl 0 GQOGOOOOOOOOO ooooooooooooo 'poco oooooooooooololooo ooooooooooooi Patented Sept. 25, 192s.

UNITED STATES JOHN T. HOYT, OF HAZLETON, PENNSYLVANTA, ASSTGNOR T UNITED FILTERS COR- PORATION, OF NEW YORK, N. Y.,

A CORPORATION on DELAWARE.

APPARATUS FOR SEPARATING LIQUID FROM PULP FIRE-RS.

Applicationmea February 1, 1924. serial No. 689,938.

This invention relates to the paper making art, and to other fields wherein the separation of solid from liquid material is desired, more especially to the step of separating theliquid from the pulp fibers for the purpose of weighing or the like, in the various Washing and changing operations which the pulp undergoes prior to being formed into a sheet of paper, or for the recovery of Waste pulp .QD from the white liquor or mill eliuent.

It is the object of the invention to provide an apparatus which will operate continuously and efficiently yto extract the liquid from thc pulp bers and deliver pulp at any desired consistency from the solution.

Another object of the invention is to, provide an apparatus by which the pulp fibers and pulp liquor maybe effectively separated without having the continuous operation u thereof interrupted by the gummy and resinous constituent ofthe pulp liquor which tends to clog the pores of an ordinary filter when used for thickening wood pulp.

Another object of the invention is to pro- :t vide an improved separating medium for 4continuous filters for separating the pulp fibers and other solids from the pulp or sludge liquor, which will permit the passage of the pulp liquor therethrough but will u) largely prevent passage of the pulp fibers,

and which will not become clogged or impervious to the passage of the pulp or sludge liquor therethrough by the resinous or gummy content of the sludge or pulp liquor.

. Another object of the invention is to provide means for stripping the deposited pulp cake from the surface of the separating medium and for simultaneously cleaning anyv adhering matter from the surface of the separator. A

ln connectionwith this latter object, a particularly important feature of the invention is the use of a separating `medium for the pulp liber and pulp liquor, consisting of a per orated plate of sheet metal or other suitable material, the perforations of which. will permit effluent water or liquid to pass therethrough but are so small that the pulp fibers mat thereon anddo not permit the pulp to pass therethrough, the material of the sheet metal plate being of such a nature that the resinous or gummy content of the pulp or other liquor does not accumulate thereon or sto the pores thereof.-

arious other objects and advantages will device.

appear yas the description of the invention proceeds. j

t Referring nowl to the drawings which will illustrate one form of embodiment of the invention,

Flg. 1 is an end view partially in section of one form of apparatus embodying the invention., e. Fig. 2 is a side view of the apparatus shown 1n Fig. l.

Fig. 3 is a detail view illustrating the operation of the pulp removing and cleaning Fig. 4 is a sectional view on aenlarged scale of a portion of the separating surface.

Fig. 5 is a similar-view showing how .the

separating medium may be applied to the apparatus. Y

Fig. 6 is a detail illustrating the passages between the vacuum compartments.

Figs. 1 and 2 illustrate an apparatus which may embody my invention, patterned after the somewhat conventional drum type rotating filter. This apparatus comprises a drum. 1,v adapted to rotate through a tank 2 resting on suitable supports 3 and containing the pulp solution or other material being separated.

Therotating drum comprises suitable rim portions 6 supported by the radial arms 7 from trunnions which are rotatedin suitable bearings on the tank 2 by means ofV a worm wheel v12, driven by the worm 14, on the end of the shaft 13, the other end of which is provided with pulleys by means of which it may be driven' by a beltconnection or the like from any suitable source of power.

A plurality of wood or metal staves 2O extend across the rim portions 6 of the drum 1 so as to form a substantially airtight partition between the inner and outer portions of the drum, and on the staves a plurality of division or spacing strips 21 running longitudinally and circumferentially of the drum are positioned. l

Certain ofthe spacing strips 21 are of solid construction so as to divide the surface of the drum into a plurality of separate vacuum compartments while others are provided with cut-out portions 21a, as illustrated in Figs. 1 and 6 to permit the vacuum to be communicated and the pulp liquor to be drawn through the same into the nearest vacuum pipe 28. i Over the spacing strips 21 the separating tlf) tion in the tank.

In the practice of my invention, I have found it preferable to apply the separating medium of perforated sheet metal in strips 22 extending longitudinally of the drum and to secure thestrips by means of screws or the like 23 along the edges thereof, to the spacing strips 21.

For eflicient separation of the-pulp fibers from the pulp liquor I have found it desirable to make the holes'or perforations 24 in the separating medium of very small diameter, approximately .020 of an inch, and to effect rapid withdrawal of the liquid I provide about 60() of these holes per square inch of the separating medium. However, it is to be understood that the invention is not limited to perforations of any particular size -or' number, but that the 4size and ynumber willl vary depending upon the nature of the material being concentrated.

The space provided between the outer surface of the s'taves 20 and the'separating medlum is provided with suitable vacuum connections, such as pipes 28 which extend through one of the trunni-ons 8 and are connected to a suitable rotary plug valve 30 such as is 4described in the patent of O. J. Salisbury, 1,259,139, Mar. 12, 1918, afvac'uum connection 32, b means of which the air in said space may be exhausted to draw the liquid through the'separating medium. Y

If desired, the valve 30 may also be provided with a pressure connection 31, andA suitable pressure pipes mayy beextended to' the spaces between the drum and separating medium whereby air under pressure maybe forced through the separating medium to dislodge the pulp ifne'cessary.

In order to effect a complete removal of the pulp from 'the surface -of the drum,rand to clean the separating. medium preparatory. to reimmersing it in the pulp solution,lI provide a rotating brush or roller 33 which e'xtends longitudinally of the drum 1 at the point where it enters the tank 2. This brush may be provided with bristles or may be a felt covered roller, and is driven to rotateso that the engaging faces of the drum 1 and the brushmove in opposite 'directions by-means of a sprocket chain 34 driven from the sprocket wheel 35 on a stud shaft 36 journaled on side of the tank 2, a belt 37 and a pulley 38 being provided to turn the shaft 36.

In order to clearly illustrate the invention, the separating medium has been illustrated with'holes of appreciable size but it is to be 'understood that when holes of .020 inch in .diameter are provided in the separator medium, they will appear of much smaller size on the actual embodiments of theinvention. In the operation of the apparatus, the drum 1 1 is rotated by means of the pulley l5 and as it moves through the pulp solution, thevsuction from the vacuum line V32 is communicated through the vacuum pipes 28to the separating medium 22 and the pulp liquor is drawn through the perforations in the -separating -medium and discharged from the pipe 32, while the pulp fibers are deposited as a layer on the surface of the drum. As the drum continues to rotate the pulp is moved'out of the solution and over the top of the drum. Depending upon the arrangement of the valve 30 the suction may ifdesired, be continued after the pulp cake is removed from the solution, to draw air through the pulp cake and reduce the moisture content thereof or the air under pressure from the pipe 31 pulp cake from the surface of the drum.

- As the drum continues to rotate, the pulp the pulp in a substantially continuous sheet from the drum and directv it onto the apron 39 from which it passes into a `suitable receptacle. l

It is to be noted here that the brush vor roller 33 is pressed against the surface of the l drum to give a complete cleaning effect to the sheet metal separatingv plate 22 so as to remove any adheringpulp vfibers or resinous material therefrom to substantially prevent `clogging of the perforation 23 as the drum continues to rotate through the pulp solution. 'After three or four months continuous-servreaches the brush 33 which is rotated tostrip do may be turned on when desired to loosen the ice, the perforations may become clogged, in

which case it is a simple matter to clean `the same by directing a Jet of steam against the surface of the drum.

It will be'seen that I have provided an ap- I 'paratus .capable of rapidly and continuously dewatering the pulp fibers contained in the "pulp solut1on, and which will not readily bev come clogged by the resinous or gummy con Ltent of the pulp liquor, or other liquor being .'ltered.

In the operation of the dewatering apparatus if the suction through the separating medium is cut off about the time thepulp leaves the solution the pulp Will contain 90 to '95% derstood that many changes and modifica' tions maybe made therein within the scope of the following claims, without'departing from the spirit and scope of the invention and that the invention is not confined solely to the lil-A other elds where tration of paper plulp but may be used in t e sticky, gummy or resinous nature of the sludge causes ordinary lter fabrics to clog up too rapidly for efficient service, it being my intention to claim the invention as broadly as the state of the prior art will permit.

I claim- 1. In an apparatus for separating liquid from pulp bers, a receptacle for the pulp 'solutionya drum extendinginto the receptacle, means to rotate the drum," a perforated smooth surfaced separating plate on the'surface of the drum, means to pass the liquid through said perforations to deposit alayer of pulp on said perforated plate in the solution, and means comprising a rotating brush to remove the deposit from the perforated plate in a substantially continuous sheet.

2. In an apparatus for separating 'liquid from pulp bers or the like, a receptacle for the solution,- a drum extending into the receptacle, means to rotate the drum, a perforated smooth surfaced separating plate on .the surface of the'.` drum, means to pass the liquid through said perforations to deposit a layer of pulp on the portion of the drum in the solution, and rotating means outside the solution for removing the layer of pulp deposited on the drum in a substantially continuous sheet.

. 3. In an apparatusfor separating liquid from pulp bers or the like, the combination of a receptacle for the pulp solution, a drum extending into the solution, means to rotate the drum, a perforated sheet metal plate on the surface of thedrum, means to create a 'suction inside the drum to dravvr the liquid through the perforations and deposit alayer of pulp bers thereon, means to out off suction from a portion of the drum outside the pulp solution and means to completely remove thepulp bers from said plate during each cycle of lter operation.

4. In an apparatus for separating liquid from' pulp bers or the like, the combination of a receptacle for the pulp solution, a drum extending into the solution, means to rotate the drum, a perforated sheet metal plate on the surface of the drum, and means to create a suction inside the drum to draw `the liquid through the perforations and deposit a layer of pulp bers thereon, means to cut olf the suction from the portion of the drum outside the solution, and a brush contacting with the surface of the drum and rotating in a direction to remove the pulp layer in a substantially continuous sheet and clean the surface of the drum.

5. In an apparatus of the type described, the combination of a receptacle, a drum extending into the receptacle, a separating medium on said drum composed of perforated 6. In an apparatus of the type described,

the combination of a receptacle, a drum extendinginto the receptacle, a separating medium on said drum composed of vperforated sheet metal plate, containing approximately 600 perforations per square inch, each perforation being about .020 of an inch in diameter means to rotate said drum, means to eect separation of the liquid and solid matter in said receptacle and deposit the solid'material on said drum, and means outside said receptacle, rotating in a direction to remove the solid material from the drum.

In testimony whereof I have aixed my signature to thisspecication.

JOHN T. HOYT. 

